225 Alternator

linckeil did you see the wireing diagram Jim posted from Painless? It shows #2 and BAT connected together.

 

I did, and in my post i said many people wire the #2 terminal incorrectly to the BAT lug on the alternator. This is wrong for the reasons I list in the original post. painless is showing you the least "painless" way of wiring it. It will work using their method, and it is slightly easier, but it is not the best way to do it. sensing voltage as it leaves the alternator makes no sense. you need to sense voltage further down stream for maximum alternator performance.

painless is a reputable company, but it is disappointing to see them issue that diagram. it will work, but it will not work as well as it would if the alternator was wired as it was designed to be.

 

Thanks, I'm going to wire it correctly before I assume the ALT is bad, but seems to me it should put out something even wired wrong but what do I know?? What should I get for the diode, I've never heard of one? I also need to go buy wire and terminals. Thank you for your help

 

you can buy a 4-pack of diodes from Radio Shack for a few bucks: Part #1N4001. install with the stripe toward the alternator.

LEGAL DISCLAIMER!!! PLEASE READ!!!
confirm everything I am saying with a reputable alternator shop before going ahead and rewiring everything. I am confident in all that i've said, but I don't want to be held responsible if anything i said doesn't work for you !!

 

LEGAL DISCLAIMER!!! PLEASE READ!!!
confirm everything I am saying with a reputable alternator shop before going ahead and rewiring everything. I am confident in all that i've said, but I don't want to be held responsible if anything i said doesn't work for you !! [/QUOTE]

No problem, by way of explanation, I bought this CJ non running. and in the process of rebuilding the motor and cleaning out a bunch of "dead" wires I probably messed up the wiring. That is why I am asking for info on how it should be. Currently there is a wire from BAT to #2. #1 goes to a keyed 12 vlts. Something is obviously wrong and before I buy a new ALT I want to at least make sure the wiring is correct.

 

What mine is missing is the wire from the BAT terminal on the ALT to the plus side of the battery. Would that keep the ALT from working??

 

OK, that was the problem, no wire to the battery. ALT is putting out good vlts now. I'm still going to add the diode though as there isn't one now.

 

I've read thru the info on the MAD site regarding the wiring issues.
Although technically correct, the info presented is also presented by a company trying to sell you something....their wiring harness/products.
Kind of like the Lucas spinning wheel/oil additive demonstration; if we can show the people, the people will buy.
There are always alternative ways to most problems.
I suppose if I had several electric fans, and tons of other electrical accessories (winch, off road lights, blender, etc etc) that draw a lot of power, I could upgrade and do as they suggest.
The Painless diagram is nothing more than a soloution to a problem. It works for me in my application. I used their harness in the rewire of my Jeep. (The alt was wired the same before I installed the Painless harness.) I didn't care to run a wire from the alternator straight over to the battery; I didn't like the looks of that ugly wire hanging across the compartment from the alt to the battery; I ran mine to the starter solenoid where it meets the positive battery cable. Just looks cleaner in the engine compartment.
I also run a voltmeter, and I suppose, where I tie in to the electrical system could/can make a slight difference in voltage read; once again, it wasn't all that important to me; the voltmeter is a gauge that reads system voltage present in the system. No matter where it is wired in the system, a low volt reading will let me know something is not right.
In my opinion, to say that this wiring method is WRONG, is, well, WRONG.
It is NOT wrong, it will NOT hurt or harm anything, and is an acceptable way of wiring your Jeep.
It's merely another way of accomplishing the same thing.
and....I believe we are splitting hairs here.....

 

jim, you are right, jumping #2 terminal to the BAT lug will work. i've said that all along. but it will not work as well as it would if the voltage was sensed downstream. for a stock early cj whose largest draw is the headlights, the difference in the 2 wiring methods is undetectible. but, if you run an electric winch, spot lights, electric fan, large stereo, etc, etc, the difference in the wiring methods will become noticable - as you mention.

I'm going to stand by my opinion that wiring it in the method described by painless is WRONG. wrong in the sense that the alternator was not designed to be wired in that manner. as i've always said, it will still work. but many things can be done the wrong way and still work, they just won't work as well as they would if they were done properly. and running the BAT lug to the stater solenoid will accomplish the same thing as running it to the postive side of the battery - thats the way I wire mine too. the problem i have with the painless diagram is jumping the #2 terminal (which senses voltage) to the BAT lug on the alternator.

it may be splitting hairs in a jeep application, but as i go threw the process of rewiring my jeep, i want to be sure to do it to maximize electrical performance. if it means having an extra wire or two running to a location that would look cleaner if the wire wasn't there, then so be it. i'd rather not sacrifice performance for looks. but again, jumping the number 2 terminal to the BAT lug is acceptable, but it's still wrong if you consider how the alternator was designed to function. i'm just trying to present all the facts as i understand them. it will always come down to the guy doing the wiring job to decide exactly how everything will be wired.

 

Guys - great discussion. Hearing different sides of this topic really is making the whole thing easier to understand for me and probably others too.
Thanks for taking the time.

 

YES!! Thanks so much. I just added the missing wire and the ALT is ALTing, 14 volts at the in dash voltmeter. Yipee!!